6.

, , :

1. = , , . 2 = 2 , , , . . , . 3 = 3 , ;

2. . , ;

3. . . . . . . .., , . . . .;

4. . . . X, - .. = X + , .., . , .. , X. ( ), . X.

1865 . .

1921 . , "" , .

1948 . . , , , , " " .

► 4

= 5

> 3?